That's why I'd prefer to buy a device with open-source hardware.
then why not get the onerng.
https://onerng.info/ you got something against it? seem like it checks off all your boxes. i doubt anything else comes close.
That looks very good, indeed! I wasn't aware of it; might even pick one up (even though I don't need a secure RNG right now).
Trezor and Foundation Devices have shown that open-source hardware is possible without your business going down due to the bad bad DIY scene.
never heard of foundation devices before you mentioned them. but i'd say these are the exception rather than the rule. then you have to ask yourself, why.
It might be easier to make money off a closed source product in the current market, where most things are closed, too.
Fortunately, open source licenses have this clause that usually requires derivatives to be open, as well. This means if you want to use Trezor's tried and tested, ancient Bitcoin crypto library, your product (firmware at least)
must be open-source too, allowing Trezor and anyone else to profit from your additions and innovations, to then further innovate themselves.
If you've never heard of Foundation Devices, you may be interested in my
review of their first device; review for the latest generation is going to be posted
very very soon, as well in the Hardware Wallet section.
I'd like to also mention
https://betrusted.io/; they built the fully open-source
Precursor so far.
Completely open-source to the very last detail.
why would it be "extremely difficult"? give me a pen and paper, i'll write down a string of 1s and 0s of length 256. i bet no one ever came up with that private key before.
Your brain won't select those 0s and 1s fully at random. It will unknowingly introduce patterns that decrease the
entropy, i.e.
how random your randomness really is.